#include <asm/paravirt.h>
#include <asm/ftrace.h>
#include <asm/percpu.h>
+#include <linux/err.h>
/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
#include <linux/elf-em.h>
#ifdef CONFIG_AUDITSYSCALL
/*
* Fast path for syscall audit without full syscall trace.
- * We just call audit_syscall_entry() directly, and then
+ * We just call __audit_syscall_entry() directly, and then
* jump back to the normal fast path.
*/
auditsys:
movq %rdi,%rdx /* 3rd arg: 1st syscall arg */
movq %rax,%rsi /* 2nd arg: syscall number */
movl $AUDIT_ARCH_X86_64,%edi /* 1st arg: audit arch */
- call audit_syscall_entry
+ call __audit_syscall_entry
LOAD_ARGS 0 /* reload call-clobbered registers */
jmp system_call_fastpath
/*
- * Return fast path for syscall audit. Call audit_syscall_exit()
+ * Return fast path for syscall audit. Call __audit_syscall_exit()
* directly and then jump back to the fast path with TIF_SYSCALL_AUDIT
* masked off.
*/
sysret_audit:
movq RAX-ARGOFFSET(%rsp),%rsi /* second arg, syscall return value */
- cmpq $0,%rsi /* is it < 0? */
- setl %al /* 1 if so, 0 if not */
+ cmpq $-MAX_ERRNO,%rsi /* is it < -MAX_ERRNO? */
+ setbe %al /* 1 if so, 0 if not */
movzbl %al,%edi /* zero-extend that into %edi */
- inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */
- call audit_syscall_exit
+ call __audit_syscall_exit
movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
jmp sysret_check
#endif /* CONFIG_AUDITSYSCALL */
/* Use %rdx as out temp variable throughout */
pushq_cfi %rdx
+ CFI_REL_OFFSET rdx, 0
+
+ /*
+ * If %cs was not the kernel segment, then the NMI triggered in user
+ * space, which means it is definitely not nested.
+ */
+ cmpl $__KERNEL_CS, 16(%rsp)
+ jne first_nmi
/*
* Check the special variable on the stack to see if NMIs are
* executing.
*/
- cmp $1, -8(%rsp)
+ cmpl $1, -8(%rsp)
je nested_nmi
/*
*/
lea 6*8(%rsp), %rdx
test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi
+ CFI_REMEMBER_STATE
nested_nmi:
/*
nested_nmi_out:
popq_cfi %rdx
+ CFI_RESTORE rdx
/* No need to check faults here */
INTERRUPT_RETURN
+ CFI_RESTORE_STATE
first_nmi:
/*
* Because nested NMIs will use the pushed location that we
* NMI may zero out. The original stack frame and the temp storage
* is also used by nested NMIs and can not be trusted on exit.
*/
+ /* Do not pop rdx, nested NMIs will corrupt it */
+ movq (%rsp), %rdx
+ CFI_RESTORE rdx
+
/* Set the NMI executing variable on the stack. */
pushq_cfi $1
.rept 5
pushq_cfi 6*8(%rsp)
.endr
+ CFI_DEF_CFA_OFFSET SS+8-RIP
+
+ /*
+ * If there was a nested NMI, the first NMI's iret will return
+ * here. But NMIs are still enabled and we can take another
+ * nested NMI. The nested NMI checks the interrupted RIP to see
+ * if it is between repeat_nmi and end_repeat_nmi, and if so
+ * it will just return, as we are about to repeat an NMI anyway.
+ * This makes it safe to copy to the stack frame that a nested
+ * NMI will update.
+ */
+repeat_nmi:
+ /*
+ * Update the stack variable to say we are still in NMI (the update
+ * is benign for the non-repeat case, where 1 was pushed just above
+ * to this very stack slot).
+ */
+ movq $1, 5*8(%rsp)
/* Make another copy, this one may be modified by nested NMIs */
.rept 5
pushq_cfi 4*8(%rsp)
.endr
-
- /* Do not pop rdx, nested NMIs will corrupt it */
- movq 11*8(%rsp), %rdx
+ CFI_DEF_CFA_OFFSET SS+8-RIP
+end_repeat_nmi:
/*
* Everything below this point can be preempted by a nested
* caused by an exception and nested NMI will start here, and
* can still be preempted by another NMI.
*/
-restart_nmi:
pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
subq $ORIG_RAX-R15, %rsp
CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
CFI_ENDPROC
END(nmi)
- /*
- * If an NMI hit an iret because of an exception or breakpoint,
- * it can lose its NMI context, and a nested NMI may come in.
- * In that case, the nested NMI will change the preempted NMI's
- * stack to jump to here when it does the final iret.
- */
-repeat_nmi:
- INTR_FRAME
- /* Update the stack variable to say we are still in NMI */
- movq $1, 5*8(%rsp)
-
- /* copy the saved stack back to copy stack */
- .rept 5
- pushq_cfi 4*8(%rsp)
- .endr
-
- jmp restart_nmi
- CFI_ENDPROC
-end_repeat_nmi:
-
ENTRY(ignore_sysret)
CFI_STARTPROC
mov $-ENOSYS,%eax